createSpyObj may use object for method->response shorthand

examples:

```JavaScript
var mySpy = jasmine.createSpyObj("mySpy", { getAge: 55, getLanguage: "JavaScrizzle" });

var age = mySpy.getAge();

expect(age).toEqual(55);
expect(mySpy.getAge).toHaveBeenCalled();
```

Also does:

Add "isObject_" method to utils to make it easier for "createSpy" to support an array or object of stubs

spec/core/UtilSpec.js

@@ -15,6 +15,22 @@ describe("jasmineUnderTest.util", function() {
     });
   });
 
+  describe("isObject_", function() {
+    it("should return true if the argument is an object", function() {
+      expect(jasmineUnderTest.isObject_({})).toBe(true);
+      expect(jasmineUnderTest.isObject_({an: "object"})).toBe(true);
+    });
+
+    it("should return false if the argument is not an object", function() {
+      expect(jasmineUnderTest.isObject_(undefined)).toBe(false);
+      expect(jasmineUnderTest.isObject_([])).toBe(false);
+      expect(jasmineUnderTest.isObject_(function() {})).toBe(false);
+      expect(jasmineUnderTest.isObject_('foo')).toBe(false);
+      expect(jasmineUnderTest.isObject_(5)).toBe(false);
+      expect(jasmineUnderTest.isObject_(null)).toBe(false);
+    });
+  });
+
   describe("isUndefined", function() {
     it("reports if a variable is defined", function() {
       var a;